$ git clone -n https://src.fedoraproject.org/rpms/gotcha.git /var/lib/mock/f40-build-792767-138594/root/chroot_tmpdir/scmroot/gotcha
Cloning into '/var/lib/mock/f40-build-792767-138594/root/chroot_tmpdir/scmroot/gotcha'...
$ git fetch origin f01df4b0befc1e0460271846d1999f1a415904c4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gotcha
 * [new ref]         f01df4b0befc1e0460271846d1999f1a415904c4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f01df4b Exclude i686 due to build failure